Heat control for industrial ovens



April 7, 1925.

H. W. PARTLOW HEAT CONTROL FOR INDUSTRIAL OVENS Filed June 14, 1924 heats-Sheet l April 7, 1925. 1,532,340

H. w. PARTLOW HEAT CONTROL FOR INDUSTRIAL OVENS Fi1e d June 14, 1924 2 Sheets-Sheet 2 )Patented `Apr. 7,. 1925.

nowann w. ranma-ow, or Urrea, New vo ET CONTROL -FOR INDUSTRIAL OWENS.

Application filed June 14, 1924. Serial No. 720,116.

useful Improvements in- Heat Controls lfor industrial Ovens, of which the following is a specification. This invention relates to improvements in x thermostatic governors, for controlling the heat of industrial and other ovens, including annealing, enameling, tempering and corebaking ovens, wherein the heat is produced by either atmospheric or high-pressure gasburners.

'The object of the invention is to provide novel, simple and sensitive means for maintaining the proper degree of heat, for eecting the baking and curing of the products of the ovens. A further object is to provide a series of valves, preferably of the balanced type, which are connected for simultaneous operation, and which are especially adapted for controlling the fuel-gas,when the latterv is consumed at pressures above the ordinary commercial pressure. A' further object is to provide a novel mechanism for opening and closing the said valves; the said mechanism being capable of controlling a relatively wide range of temperatures in ovens, and the like, and being arranged for adjusting and "setting the said valves and certain related parts, for accurately predetermining different degrees of `/teinperatura .A further object is which is operatively connected with the valve operating and adjusting mechanisms, and which may be disposed in a hot zone of the oven, for automatically controlling the said valves. And a further object is to provide a combined mechanical and thermostatic heat control which e'ectually obviates excessive heating, as well as waste of the fuel. rlhe various', features and parts of the invention will 'be understood from the detailed description. which. follows, and by reference to the accompanying drawings, in which- Figure l is a reduced top-plan view of the complete governor, embodying my. improvement. Figx is a front side elevation to provide a thermally actuated element,

of the same'. Fig. 3 is a front end elevation of the device. Fig. 4 is an enlargw front yface view of the indicating dial. Fig. 5 is a vertical longitudinal section, taken 55 on line 5--5 of Fig. 3. Fig. 6 is a vertical cross-section, taken Online 6--6 of Fig. 5. Fig. 7 is a front elevation. of an oven to which my governor Ais applied. And Fig..

8 is a horizontal section, taken on line8-8 6o of Fig. 5.

lnthe drawing, 2 represents a hollow body, adapted to. be mounted on an oven, as shown in Fig. 7, the said body having a normally open end, which is closed and e5 sealed by a removable cap 2, which isv held in place by screws 2a, andy having a bottom opening 2b, and a side opening 2e, for adondmg access to the interior, for assembling and inspection; the latter openings being 70 closed by screw plugs 2d. The body 2 directly controls the supply of fuel gas to the oven burners, and for this purpose, said body is `charged with the pressure by means of av pipe 3, which isscrewed into 75 the rearside of the body, andv discharges the gas into a relatively small inner cham.- ber l, which is preferably formed by an integral wall 4'., and from which the gas is fed to the burners of the oven by a pipe 5, that taps the lower end-portion of the body as best seen in Fig. 5. The outer end o pipe 5 is provided with a l 5', to which;

lplpes a-b connect, Ifor carrying the fuel gas in dierent directions towards separate burners simultaneously. The chamber [i is also tapped by a pipe 6, which with a cock 6', forms a by-pass adapted to supply a small volume of the gas, for preventing the extinguishment of the burners {rf-5d, dur- 9o ing the intervals between the periodical nringa'- The pipe 6 is composite, consisting of several nipples and elbows, which dischargesy the gas into the top of the ,casi` 2, 'throughfan opening 2, to be carried to 95 the burners by the pipes 3a-5". The fuel gas for heating the oven is'supplied intermittently, accordingly as the temperature of the oven -ductuatea by means of twin valves IJ-7', the latter preferably being ico Y spherical, and being flexibly connected, by

`[means of 'loosely arranged links i7, which permit independent movement and adjustment of the valves relatively to each other, as well as to their seats 4a. The seats 4:8 are both disposed at thetops of individual outlet passages 4th-4, which communicate with the interior of thel casing 2, in which the balls 7 7' play vertically; the said seats alining axially and being so arranged that the gas exerts its pressure for seating the uppermost ball 7 and for unseating the lowermost ball 7 simultaneously, thereby efecting the balancing effect, which is desirable, when the gas is burned under conslderablev pressure during intensive heating.

The valves 7-7' are raised towards their seats by a link 7, whose lower end is swiveled to the valve 7, by a pin 7d. The top end of link 7c is pivoted to the rear-end of' a link 8, by a screw 8', the latter link being pivoted intermediate its ends, bya screw 8a, to the horizontal arm of a belly crank 9, which in turn is pivoted to a i'orked stud 10 carried by the cap 2'. rlhe forward end of the link 8 is pivoted to the -top end of a similar link l2, by a screw 12', while the bottom end of the latter link is pivoted, by a screw 12a, to the horizontal arm 13 of a bell crank 13. The vertical arm 18a of the lattercrank isfpivoted by a screw 13, to a block 14, which is rigidly secured to the inner wall of the casing 2, adjacent a threaded opening 2f. The thermostat that controls the temperature of the oven is in I two parts, and comprises a relatively long corresponding end of the tube15; the latinto the bushing 15, said rod may be read-.

ter end being closed and protected by a screw -cap 15. iBy threading the rod 15 ily and linely adjusted relatively to the bell- 'crank 13,-for accuratelyy and sensitively con- .The vertical arm of the bell-crank 9 is pivoted in the forked head Aof a screw or worm 16, which passes through themap 2' and projects into the leasing 2 above the -stud 10. The threaded portion of thescrew 16 extends outwardly throughV a hollow boss ",17, which is preferablyan integral part ot' the cap 2'. The screw 16 isreciprocated by means of an elongated nut 18, whose enlarged inner end or'head'seats against the bottom of the cavity17' of the boss, while \the stem 18a by a screw .21.

ybell-shaped sleeve 20', which isrotatably supported by the boss 1.7. `The contracted outer end of the sleeve receives the stem 18a' of the nut, and uponthis reduced portion is mounted a disc or knob, by which the dial is manually rotated, for rocking the bellcrank 9. The disc 21 is rigidly secured to The threads of the screw 16 and the nut 18 are preferably of relatively steep pitch, so that the adjustment of the dial 20, for predetermining temperatures within a relatively wide Drange may be effected by a single revolution of the dial and nut 18. ln order to limit the revoluble action of the dial, I provide a stop pin 22, which is supported by (the cap 2', parallel to the `axis of the dial, and the dial is fitted with a radial arm 22', which contacts with the pin 22, for/stopping the dial, when the latter rotates in either direction `a full turn, as shown in Fig. 4. The dial is formed with an interrupted concentric slot 20, for facilitating applying adjustable temperature indicating tags or plates 223-23', upon which may be stamped numbers indicatlng maximum and minimum degrees of temperature the device is intended to control` as indicated in Figs. 3 and 4. The tags 23-23 are held in place by screws 23", which passthrough the tags and the slot 20, and are detachably secured by nuts 23 (see Figs. 2 and 5).

The valve controlling mechanism comprising the links 7 and 8, bell-crank 9, link 12 and bell-crank 13, may be operated either by hand-knob 21 and screw 16, or by the thermostat 15-15', for opening and closing the valves 7--7. The full lines in Fig. 5 show the normal position of the bell-crank 9,

which is directly controlled by the handknob 21. The dotted lines in the same view, Show the operation of the said crank, for predetermining higher or lower than normal temperatures. If the bell-crank 9 is tilted by the inward moifement of the screw 16, when the valves 7-7' are open (seeldot-- ted lines in Fig. 5), and the bell-crank 13 is.

held stationary in either of the positions shown in Fig. 5, the crank 9 will rock the j link 8 on the pivot 8a in the direction rfor lifting the link 7, and the valves upwardlyA towards their seats. By this arrangement,

the valves may be adjusted relatively to their a seats in advance of a heating period, or during the said period, for limiting the ultimate control of the valves by the thermostat 15-15, through the crank 1 3, and thus predetermine the range of temperature of an oven or other thing that is being governed. For example: Assuming 2 that the valves 7-7 are open, as shown by the dotted lines in Fig. 5, and are yielding a temperature of 450F., by reason of a prior adjustment,

' and it is desired to reduce the maximum temperature to 400, the operator should first turn the knob 21 and the dial in the direction for bringing the indicating tag 23 into registry with the pin H22. This rocks the bell-crank 9 towards the left for tilting the near end of the link 8 downwardly. and,

lowers its horizontal arm, which pulls down` ,wardlydn the link 12, and rocks link 8 in the direction for seating the valves 7-7 and shutting olf the iow of the fuel gas. When the temperature of the oven falls a degree or so, the thermostat correspondingly contracts, and reverses the movements of the several parts referred to, and opens the registry with the pin 22.

tilting of the crank 9 in the opposite direcvalves, for allowing fresh fuel to pass from chamber 4 to the burners, for again raising the temperature in the oven to the predetermined maximum, and s on.` On tlieother hand, if the oven hasbeen operatin Iat a .maximum temperature of 400, as in lcated by the position of the `tag 23 in Fig. l4, and it is desired to increase the maximum Vtosay, 450, the operator may rotate'the dia-120 in the direction for bringin his will effect the tion, and rock link 8 and link 7 in the direction for lowering the valves 7-7 still farther from their seats. This latter adjustment will cause theA burners to operate at full blast a longer interval, to raise the temperature of the oven 50, and require the thermostats to expand to a greater extent, in order to seat the valves 7-7 and shut down the burners, when the new maximum temerature (450) is reached. In either case escribed, the valves 7-7 'will be closed' when the maximum heat indicated b the indicating dial has been roduced. vIt 1s obvious that the valves 7-5 ma be closed by the `manipulation of the ldia 20; or said .valves may be closed by the expansion of the thermostats, provided the firing of theburners iscontmued for a long enough period and the heatevolved by the burners is sufficient to effect the required ex anson of theP members `15-15, as describe said predetermining the tag 23 linto.

fin the gas rece1ving governor adapted to oven 24, which is heated by the burners 5-5d, which are shown located at the oppo.-

site lower sides of the oven, andconnect respectively with the modified gas-supply pipes 58h-i3".6 The governor is preferably mounted on one of the doors, as 24', and the thermostat is accordingly close to the top, or the hottest zone of the oven. The governor is shown equipped with flexible gas tubes 3 and 5, which permit the door 24 to be swung open, without interfering with or injuring the connections. The governor. may l be disposed in any other suitable'position.

Having thus described my invention, what I claim, is- A 1. A heat/governor, comprising a hollow body adapted to be charged with fuel gas to be delivered to burners for producing theY heat, a primary gas receiving chamber lwithin said body, a 'thermostat supported y serted in the zone of the heat evolved by the burners, a mechanism for predetermining maximum and minimum degrees of heat to be controlled by the thermostat, located at one end of the body adapted to be iny.

the opposite end of the body, apair of valves in said receiving chamber, said valves being flexibly and adjustably connected and being arranged for simultaneous operation for controlling the outflow of the fuel gasv towards the burners, and a series of connected links interposed between and operatively connecting said thermostat and mechanism with each other and with said valves.

2. A heat governor, comprising .a hollow 4body adapted to be charged with fuel gas to be deliveredto burners for producing the heat, a gas receiving chamber located wlthin the hollow body, athermostat supported said 'body adapted to be inserted in a zone of the heat evolved by burning said gas, an indicating dial for predetermining maximum land minimum degrees of kheat controlled by said thermostat. mounted on said bod a pair of flexibly connected valves arrange for operation as one part disposed chamber adapted for dispensing the fuel gas during the heating periods, a bell-crank operatively connecte with said dial, a bell-crank connected to the thermostat, and a series of pivotall'y connected links operatively connecting said bell-cranks with each other and with saidV valves, whereby said thermostat, as well as eiect the opening and closing movements of the valves. v l

gasa' with its interlor bj1-.separate ports, aAV

120 said dial may jointly and independentlyA 3; The combination with an loven and Fig. 7 represents conventionally baking pair'vof flexibly connected valves in said 13 chamber adapted to control the iow of the gas from said chamber into said body, means for adjusting said mvalves relatively to each other and to their seats, neans for conducting t-he fuel gas from the body to said burners, `a thermostat carried by said body adapted to be inserted in the oven and to expand and contract for positively conf trolling the opening and closing of said Valves, a mechanism including a bell crank for predetermining the range of the opening and closing movements of said valves, and a series of pivotally connected links operatively connecting said thermostat and said' mechanism with said Valves. f

4. A governor for controlling the temperatures of ovens and the like, including a hollow body adapted to be charged with fuel gas, said body having a separate chamber that receives the gas from its source of supply, s aid chamber communicatingwith the interior of thelbody by several ports, a valve for controlling each port, said valves being flexibly connected for simultaneous operation, means for adjusting said valves for predetermining the range of-the open ing and closing Ymovementsithereof, and a thermostatic element associated with said body arranged to be inserted in the hottest zone of the oven adapted to effect the opening and closing of said valves to the extent limited by said predetermining means. 5. A governor for controlling the temperature of ovens and the like, including a hollow body adapted to be charged with fuel-gas to be su plied to the burners of theoven, said bodly having an inner chamber that receives the fuel-gas'froml its source,

said chamber communicating with the/inf terior of the Abodyby' a series of ports 'a valve for controlling each port, adjustable means connecting said valves for operation as one part, an indicating Vdial adapted for predeterminin maximum-and minimum degrees of heat 1n the oven, a bell-crank op- 'erativelyI connecting said dial with said valves, a thermostat `carried by said body arranged to be inserted in heated portions of the oven, a bell-crank operatively connecting the thermostat with said valves adapted to open and close the valves when the temperature in the oven reaches the minimum and maximum degrees indicated I by said dial,l and means'interposed between in said chamber for dispensing the gas via said ports, said valves being flexibly connected and operable simultaneously, a thermostat' arranged to beinserted in'an oven and adapted to control .said valves to a limited extent by its expansion and. contraction, means for predetermining and indicating various temperatures to be cont-rolled and closing movemens of said heat inthe oven, a bell-crank operatiyely connected with said dial, a thermostat ear- -ried by said body adapted to be inserted in a hot zone of the oven and adapted to control said valves to the extent limited by said y.predetermining means, a bell-crank operatively connected `to said thermostat, and a series of links connecting said valves with both of said bell-cranks, whereby said dial and said thermostat may jointly effect j the maximum movements of said valves. j

8. In a heat Acontrolfor ovens, a hollow body adapted to be charged with fuel gas for supplying the burners of the oven, flexibly connectedl valves in said body for controlling the How of the gas to the burners, an indicating mechanism for predetermining the range of temperature in the oven, \a bell-crank operatively connected with said mechanism, a thermostatic element carried by said body adapted to be inserted in a hot zone of the oven, a bell-crank operatively connected to said element, and a series of links connectin said valves with both of said bell-cran s, whereby said mechanism and said element jointly effect the maximum movements of said valves for controlling the heat of the oven.

9. In a heat control for industrial ovens, the combination with an oven and separate burners for heating the oven, of a hollow body adapted to be charged with fuellgas to be supplied to theburners, said'body having an innen chamber communicating with the interior of the body by means of alining ports, flexibly connected valves disposed in said chamber adapted to dispense the fuel 'gas via said ports, means for adjusting said valves relatively to each other and'to their seats, a rotary indicating dialJ mounted on said-body adapted for predetermining the ran of temperature in the oven, a series of' operatively connected with said valves, adjustable means connecting said stat with said links, and a by-pass tapping links with said dial, a thermostat supported said chamber adapted to provide small by 4said body arranged to be inserted in the quantities 0f gas toSad body When Said 10 hottest vportion of the oven adapted to ex- Valves are CIOSedp* 5 pand and contract by the rise .and fall of In testimony whereof I ax my signathe temperature in said oven, a rockable tlll'epart operatively connecting said thermo- HOWARD W. PABTLOW. 

